This section provides background information related to the present disclosure which is not necessarily prior art.
Filters are commonly used in various applications to ensure that a liquid meets a certain standard of purity or cleanliness. For example, various fluids such as gasoline and hydraulic fluids can be filtered to ensure that there are no particles in the fluid that might damage an engine or a pump. In some cases, various gases such as an exhaust gas can be filtered to minimize the pollution generated by an engine. Applications in which such filters are used are numerous and include various vehicles such as airplanes, automobiles, tractors, farm equipment, construction equipment, and other machinery.
In a typical application, fluid flows through a filter, which removes foreign matter or particles from the fluid. These filtered particles accumulate in the filter element. As these particles accumulate, the filter element becomes plugged or clogged and loses its effectiveness. As a result, an amount of particulate matter in the fluid that escapes through the filter may increase to an unacceptable or hazardous level and may damage the equipment using the fluid or may allow an unacceptable level of contaminants to escape into the atmosphere.
One example of a device used to monitor the effectiveness of a filter is a differential pressure gauge. Such a gauge can be used to monitor the fluid pressure on each side of a filter element. As the filter element becomes plugged, the pressure differential across the filter increases accordingly. For example, piston-type differential pressure gauges are frequently used to monitor filter differential pressure. A user is typically required to visually monitor the reading of such gauges.
Use of electronic data acquisition systems has increased dramatically, and sensors are often required to have electronic outputs to work with these systems. Various electronic differential pressure transducers are available to provide this data. However, piston-type differential pressure gauges have a very large existing user base for monitoring filter differential pressure, particularly for aviation fuel filter uses, and these gauges do not provide electronic output for use with electronic data acquisition systems. For example, it is estimated that thousands of such gauges are currently in operation for monitoring aviation filter differential pressures.